Ground vehicles, such as cars, sleds and the like have already been proposed, built and used in the past. Cars also had already hydraulic motors for driving wheels. Boats have already been driven by air-propellers. Aircraft have already been proposed to be supplied with propellers to be driven by hydraulic motors.
However, these proposals of the prior art devices suffered from certain disadvantages which were never overcome. Some devices used a single working chamber group in their fluid flow supply device and split the resulting fluid stream into a plurality of flows; this resulted in a loss of control over the synchronization of the rotary velocity of the individual propellers. Others of the devices of the former art employed control communication between their several fluid lines, which could result in unequalness of rate of flow in the fluid lines. In either case, the control of such vehicles could become unstable and could prevent the effective and safe use of fluid stream-driven vehicles.
One of my above mentioned patent applications obtained a parallel patent application for a hydraulically operated aircraft, which is now my U.S. Pat. No. 3,823,898. From said patent it might assumed on a first glance, that ground borne vehicles might act as said aircraft of said patent. That however is not the case. The aircraft has a side radder for the control of its straight forward movement. The ground borne vehicle of my present invention does not need and does not have such radder. Its movement and movement direction is exclusively controlled by the equalness of thrusts symmetrically on opposite sides of the longitudinal vertical medial face of the vehicle. While an aircraft starts from a solid ground on an airbase, the vehicle of the invention will be controlled on slippery, unholding ground as well as on solid ground.
A conventional car for example can not travel by wheel drive on slippery ground, because the wheels would slip. A sled can not move an ascending way, when its driven snow mobile tracks slip on the snow.
An aircraft on the other hand is assumed to fly at high speed. At such high speeds its radder control works effectively. On ground however, during start or landing, the aircraft is mainly kept stright by the combination of plurality of control-actions, like radder control, strightly set wheels and throttle control of the engines. Since an aircraft has no definite exact direction control at low speed it requires a wide and long runway.
The ground borne vehicle of this invention is however not assumed to run exclusively on good solid highways or on good solid runways of airports, but on contrary also, or even mainly, on slippery unsolid ground. On such unsolid ground the vehicle of the invention must get a strong thrust force and a strong capability of directional control. That is different from the ordinary use of cars, sleds, aircraft and like.
In order to achieve a desired drive means for a vehicle of the invention different actions apply, which are different from those in cars, sleds or aircraft.
On the slippery ground, whereon the vehicle shall be able to travel, the drive means can not rely on any ground-traction means. The vehicle can also not rely on any holding of strightness of movement by ground-guide-or holding-means. The vehicle of the invention can also not rely on the common single air craft propeller for its drive. Because the common single propeller of an aircraft is effective only at high speed. The losses in common aircraft propeller drives would be too big in a vehicle of the invention and its thrust force for forward move would become to small.
To overcome those difficulties the vehicle of the invention applies a plurality of propellers arranged symmetrically opposite of the longitudinal medial plane of symmetry in order to abtain a higher thrust for the vehicle at a given power installation and the invention applies equalness of rate of flow in fluid lines in order to achieve equalness of rotary velocities and thereby of thrusts of the plurality of said propellers. A powerful stright forward drive of the vehicle is thus achieved by the invention and respective control means for driving courves may be added.